1. Field of the Invention
The present invention relates to a tape cassette having a plug member and an identification hole to identify predetermined matters from a depth of the identification hole and a color of a predetermined depth position of the identification hole by opening and closing the identification hole in accordance with movement of the plug member.
2. Description of the Related Art
FIG. 1 of the accompanying drawings shows a tape cassette having a plug member of this kind. FIG. 1 shows an 8-mm video cassette used in an 8-mm video camera. As shown in FIG. 1, this 8-mm video cassette includes a cassette housing 1 composed of an upper cassette shell 2 and a lower cassette shell 3 fastened together by some suitable means (not shown). The cassette housing 1 incorporates a supply reel and a take-up reel on which a magnetic tape may be wound and a part of the magnetic tape is exposed to the front wall of the cassette housing 1, though not shown. The magnetic tape is exposed to the front wall of the cassette housing 1 and this front wall can freely be opened and closed by a cassette lid 4 pivotally attached to the front portion of the upper cassette shell 2.
The cassette housing 1 has a rear user label area 5 formed on the rear surface thereof. A mis-erase prevention indication window 6 is formed on one side of the rear user label area 5. The mis-erase prevention indication window 6 can be opened and closed by a mis-erase prevention plug 7 made of a material of red color. The mis-erase prevention plug 7 can be accommodated in a plug accommodating portion (not shown) formed on the inside of the mis-erase prevention indication window 6 so as to become freely slidable. The lower cassette shell 3 has a mis-erase prevention detection hole 8 defined on the lower surface thereof in association with the plug accommodating portion. The mis-erase prevention detection hole 8 can be opened and closed by the mis-erase prevention plug 7. Therefore, it is possible to open and close the mis-erase prevention detection hole 8 by sliding the mis-erase prevention plug 7 through the mis-erase prevention indication window 6.
With the mis-erase prevention indication window 6 formed on the rear surface of the cassette housing 1, it becomes possible for the user to slide the mis-erase prevention plug 7 and to visually identify the plugged state of the mis-erase prevention plug 7.
When the cassette housing 1 is loaded above a mis-erase prevention detection mechanism (not shown) and information is recorded and reproduced, the mis-erase prevention detection hole 8 defined on the lower surface of the lower cassette shell 3 serves to determine whether or not information can be recorded on a magnetic tape incorporated in the cassette housing 1. Therefore, when the 8-mm video cassette is loaded on a so-called mechanical deck, such as an 8-mm video camera or the like, a detection pin of the mis-erase prevention detection mechanism is inserted into the mis-erase prevention detection hole 8. Then, based on detected results obtained when the difference of depths of the mis-erase prevention detection hole 8 are detected by the detection pin, i.e., detected results obtained when it is determined whether the mis-erase prevention detection hole 8 is closed or opened by the mis-erase prevention plug 7, it is possible to determine whether or not the 8-mm video cassette is in the recordable state.
The plugged state of the mis-erase prevention plug 7 in the 8-mm video cassette thus arranged will be described below.
When the 8-mm video cassette is in the recordable state, the mis-erase prevention indication window 6 on the rear surface of the cassette housing 1 is fully opened to make it possible for the user to visually confirm the inside of the mis-erase prevention indication window 6 of the same red color forming a part of the cassette housing 1. Concurrently therewith, the mis-erase prevention detection hole 8 defined on the lower surface of the lower cassette shell 3 is closed by the mis-erase prevention plug 7 and therefore the mis-erase prevention hole 8 becomes shallow. Accordingly, the detection pin is not engaged with the mis-erase prevention detection hole 8, whereby the mis-erase prevention detection mechanism can detect the recordable state of the 8-mm video cassette. Also, it is possible for the user to detect the recordable state of the 8-mm video cassette by visually confirming the color (same color as those of the upper and lower cassette shells 2 and 3) of the inside of the opened mis-erase prevention indication window 6.
When on the other hand the 8-mm video cassette is not in the recordable state, the mis-erase prevention indication window 6 is closed by the mis-erase prevention plug 7 and the red color of the mis-erase prevention plug 7 becomes able to be visually confirmed. Therefore, it becomes possible for the user to visually confirm based on a difference of colors of the mis-erase prevention plug 7 and the upper and lower shells 2 and 3 that the 8-mm video cassette is not in the recordable state. Concurrently therewith, the mis-erase prevention detection hole 8 of the lower cassette shell 3 is opened and the mis-erase prevention detection hole 8 becomes deep. Accordingly, the detection pin is engaged with the mis-erase prevention detection hole 8 and it is possible for the user to detect based on the action of the detection pin 8 that the 8-mm video cassette is not in the recordable state. In this case, the color of the inside of the mis-erase prevention detection hole 8 is changed from the red color of the mis-erase prevention plug 7 to the color of the upper and lower cassette shells 2 and 3. Therefore, the user is able to visually confirm based on the difference of colors that the 8-mm video cassette is not in the recordable state, similarly.
The same assignee of the present application has filed Japanese patent applications Nos. 57-277302 and 06-027561 (corresponding U.S. patent application also was filed), Japanese patent application No. 05-280704 (corresponding U.S. patent application and European patent application also were filed). Further, the same assignee of the present application has the U.S. Pat. No. 5,065,955.
Since however the above-mentioned tape cassette includes the mis-erase prevention detection hole 8 defined on the lower cassette shell 3 of the cassette housing 1 to detect from under the cassette housing 1 whether or not the 8-mm video cassette is in the recordable state, the so-called mechanical deck has to dispose a mis-erase prevention detection mechanism on the thickness direction of a tape cassette loaded thereon. Therefore, the dimension of the mechanical deck is increased in the thickness direction of the tape cassette, hindering the mechanical deck from being miniaturized. Because it is not possible to miniaturize the mechanical deck, it is desired to provide a tape cassette whose recordable state can be detected from the side surface of the cassette housing 1.
When the recordable state of the tape cassette is detected from the side surface of the cassette housing, it is not preferable to modify the detection mechanism greatly and the detection mechanism is generally formed of a system similar to the detection mechanism of the tape cassette in which the recordable state of the tape cassette can be detected from the lower cassette shell 3 side. With this arrangement, a space portion formed on the inside of the mis-erase prevention indication window serves also as a side surface mis-erase prevention detection hole (simply referred to hereinafter as "side surface detection hole") so that, when the mis-erase prevention hole (simply referred to hereinafter as "lower surface detection hole") defined on the lower surface of the lower cassette shell 3 is opened, the side surface detection hole also has to be opened.
In the above-mentioned tape cassette, when the side surface detection hole is opened by sliding the mis-erase prevention plug 7, the lower surface detection hole is closed. On the contrary, when the side surface detection hole is closed, the lower surface detection hole is opened. There is then the problem that the tape cassette having the plug member structure cannot be used as the tape cassette of the side surface detection type as it is.